Select the model. Let’s first talk about how the tire model is marked. For example: 195/65R15. Its specific meaning is that 195 represents the width of the tire, and 65 represents the height/width of the tire*100 (flat Ratio), R represents the tubeless tire, and 15 represents the rim diameter. Of course, there will also be the load of the tire and the speed level of the tire. Generally we don't need to think about it specially. Once we know the meaning we can start to choose. If you are an ordinary user, the rims have not been upgraded, and you are not interested in the car's grip and sports performance, then look at the model (tire side) on the original car, and then buy one of the same size. If you are a car owner with personality and who likes sports, you will have a lot of room for choice. Without upgrading the wheels, you can choose tires with a low aspect ratio. For example, you can replace the tires in the example with 195/50/15 tires. If you upgrade your wheels, choose a low aspect ratio tire based on the rim diameter. Of course, what are the benefits of upgrading wheels and tires? I think 1. Beautiful appearance. 2. The increased tread contact area improves grip and braking performance. 3. The sidewall width of the tire with a lower aspect ratio is reduced, the carcass deforms less when turning, the form is smoother, and the cornering control is improved. . Principles for tire upgrades: The tire diameter should not increase by more than 1.5% compared to the original tires. This is to ensure the accuracy of the odometer reading. There are many brands of tires on the market, including MICHELIN, GOODYEAR, BRIDSTONE, YOKOHAMA, DUNLOP, FIRELLI, Continental, Kumho, Hankook, BFGOODRICH (a brand of Michelin) Brand) ADVAN (a Yokohama brand). The product characteristics of each company are also different, but through use we will also reach one company, that is, Michelin's tires are relatively soft and have a short lifespan. And the noise will be lower. GOODYEAR tires are harder and have a longer service life. Bridgestone's tires are somewhere in between. The remaining DUNLOP, ADVAN, and FIRELLI are mainly due to their better sports performance. The overall performance of Continental will be higher, and it is mainly used in high-end cars such as Mercedes-Benz and BMW. Domestic brands have a certain advantage in price. Therefore, you should determine the brand of tires according to your own economic strength and use. Choosing Patterns The design of patterns is mainly to ensure several properties of the car: 1. Driving performance (grip), 2. Comfort (noise reduction), 3. Safety (drainage). Generally, tires have transverse and longitudinal grooves. The longitudinal grooves are mainly to ensure good drainage, while the transverse patterns are used to ensure grip, but also to take into account drainage and noise control. Different variations of patterns are the core content of each company's design, and different pattern combinations will have different usage characteristics. Sports patterns are designed taking into account the sports performance of the car. Generally, sports tires are unidirectional, which means they have a certain directionality, so special attention should be paid when installing them. Of course, we will also see tires without patterns in F1 and other car events. This is because the road surface of the track is relatively smooth, and they use hot-melt tires. As the name suggests, under a certain temperature, the surface will melt, so It can have closer contact with the ground, thereby achieving better grip.